Similar polysomnographic pattern in primary insomnia and major depression with objective insomnia: a sign of common pathophysiology?

Risk of Comorbid Insomnia Disorder Associated with Major Depression in Apneic Patients: A Cross-Sectional Study

Given the limitations of available studies, the objective of this study was to explore the role played by current and remitted major depression in the occurrence of comorbid insomnia disorder for apneic patients. Data from 1488 apneic patients were extracted from the medical reports of polysomnographic recordings available in the database of the Sleep Laboratory. The presence of comorbid insomnia disorder in these apneic patients was defined based on the diagnostic criteria of the American Academy of Sleep Medicine Work Group. The risk of comorbid insomnia disorder associated with current or remitted major depression in apneic patients was investigated using multivariate logistic regression models. After adjustment for the main confounding factors, multivariate logistic regression analyses revealed that remitted and current major depression were significantly associated with the occurrence of comorbid insomnia disorder in apneic patients. The findings of this study seem to indicate that comorbid insomnia disorder could be a residual symptom and a marker of major depression in apneic patients, which justifies the establishment of an adequate treatment for major depressive episodes and their potential residual symptoms to allow the better management of comorbid insomnia disorder and the better prevention of its potential negative consequences in this particular subpopulation.

Exploring emotional regulation in insomnia with and without major depressive episode

Previous studies have highlighted the pivotal role of emotional regulation impairment in the progression of depressive and insomnia disorders, individually. Nevertheless, to date, no study has undertaken a direct comparison of the emotional profiles in individuals experiencing insomnia with or without major depressive episode (MDE). In this study, our objective was to closely examine multiple aspects of emotional regulation among individuals experiencing insomnia, with or without concurrent depression. This descriptive observational study involved 57 participants, comprising 27 individuals with comorbid chronic insomnia and MDE, and 30 with chronic insomnia alone. All participants completed self-questionnaires assessing aspects of emotional regulation: the Affect Intensity Measure (intensity), Affective Lability Scale (lability), Temperament Evaluation of Memphis Pisa Paris and San Diego Autoquestionnaire (temperament), Cognitive Emotion Regulation Questionnaire (cognitive strategies), and Multidimensional Assessment of Thymic States (reactivity). There were statistically significant differences between the group with insomnia with MDE and insomnia without MDE in terms of anxiety/depression lability. Discrepancies also manifested in terms of activation or inhibition in motor activity and motivation. Additionally, a noteworthy variance in cognitive strategies for emotional regulation was observed, specifically in self-blame and catastrophising. From a cognitive perspective, patients with insomnia and a MDE exhibited a greater inclination towards self-blame and catastrophising, in contrast to those with insomnia only. Behaviourally, the former group demonstrated heightened inhibition of motivation and motor activity. These findings underscore the importance of larger-scale investigations to validate these insights and pave the way for clinical prospects centred around emotional regulation, ultimately fostering personalised treatments for insomnia.

Cardiovascular Outcome in Patients with Major Depression: Role of Obstructive Sleep Apnea Syndrome, Insomnia Disorder, and COMISA

In this study, the 10-year cardiovascular risk associated with comorbid sleep disorders (insomnia disorder, obstructive sleep apnea syndrome, and COMISA [comorbid insomnia and sleep apnea]) was investigated for patients with major depression. To enable our analysis, 607 patients with major depression were selected from the data register of the Sleep Unit. High 10-year cardiovascular risk was considered present when the Framingham Risk Score was ≥10%. The 10-year cardiovascular risk associated with comorbid sleep disorders has been assessed using logistic regression analyzes. High 10-year cardiovascular risk is significant (40.4%) in patients with major depression. After successive introduction of the different confounders, multivariate logistic regressions showed that for patients with major depression high 10-year cardiovascular risk was significantly associated with COMISA but was not significantly associated with insomnia disorder or obstructive sleep apnea syndrome alone. Thus, these results highlight the existence of a negative synergistic action between insomnia disorder and obstructive sleep apnea syndrome on the 10-year cardiovascular risk in patients with major depression, which demonstrates the importance of researching and treating COMISA to improve the prognosis of this specific population subgroup characterized by higher cardiovascular morbidity and mortality.

Polysomnographic features of insomnia occurring in major depressive disorder, generalized anxiety disorder and bipolar mania: Comparison with primary insomnia and association with metabolic indicators

BACKGROUND

Insomnia is very common in psychiatric disorders, but the polysomnographic (PSG) characteristics of insomnia in various psychiatric disorders are still not agreed upon. This study aimed to investigate the characteristics of PSG and its relationship with metabolic indicators in insomnia patients with affective disorders and primary insomnia (PI) patients.

METHODS

A total of 38 patients with PI, 44 major depressive disorder patients with insomnia (DI), 49 generalized anxiety disorder patients with insomnia (GI), and 19 bipolar mania patients with insomnia (BI) were included. PSG was used to detect sleep problems in subjects, and biochemical indicators were also collected.

RESULTS

The results of this study found that subjects with BI were lower on REM sleep latency (RL), awakenings number (AN), number of microarousals (NM), and apnea-hypopnea index (AHI) than those with DI and GI, and lower on RL and AN than those with PI. Subjects with PI had lower NM and AHI than those with DI and GI. Patients with DI had a higher RL than those with GI. All results passed Bonferroni correction (p < 0.00078). No differences in biochemical indices were found among the four groups of subjects. Also, AHI was found to be positively correlated with free triiodothyronine (FT3) and fasting blood glucose in subjects.

CONCLUSION

This study suggests that various psychiatric disorders may have their characteristics in terms of PSG parameters, which prompted us to focus on the PSG characteristics of these disorders when assessing them, as well as to focus on their biochemical indicators.

Effects of insomnia on risky driving behavior among bus drivers: The mediating effect of mental health

Crashes caused by problems with bus drivers' physical and mental health have increased in frequency in recent years. Insomnia, a common type of sleep problem, has significant positive relationships with both crash risk and mental health problems, especially anxiety and depression, which are themselves associated with driving behavior. However, few studies have conducted analysis on sleep-related problems and mental health exclusively on bus drivers, nor on how these problems influence driving performance. Thus, this study explored the effect of insomnia and mental health on bus drivers' risky driving behavior and evaluated the interaction of four variables: insomnia, anxiety, depression, and risky driving behavior. The survey-based investigation was conducted in a bus company in Suzhou, China, with 1,295 bus drivers participating. Insomnia, anxiety, and depression were self-reported based on professional mental health scales and risky driving behaviors were measured by the Driver Behavior Questionnaire. Two mediation models and a chain mediation model were developed to examine relationships among the bus drivers' insomnia, anxiety, depression, and risky driving behavior. Results revealed that (a) bus drivers less than 31 years old, drivers with more than 11 years' experience driving buses, and those with crash and violation involvement within three years demonstrated more severe degrees of insomnia, anxiety, depression, and risky driving behavior; (b) there were significant positive correlations and interactions among the four variables. Results specifically related to the interaction among variables include findings that (a) anxiety mediated between insomnia and risky driving behavior; (b) depression mediated between insomnia and risky driving behavior; and (c) anxiety affected bus drivers' risky driving behavior primarily though depression. The findings in this study indicate the importance of regular physical and mental health examination of bus drivers and suggest that interventions focused on insomnia and mental health problems may be helpful to reduce risky driving behaviors of bus drivers both directly and indirectly.

Neural substrates underlying REM sleep duration in patients with major depressive disorder: A longitudinal study combining multimodal MRI data

INTRODUCTION

Prior studies have discussed rapid eye movement (REM) sleep disturbance as a potential endophenotype of major depressive disorder (MDD). However, the neural substrates underlying the percentage of REM sleep duration (REM%) and its association with disease progression in MDD remain unclear.

METHODS

One hundred and fourteen MDD patients and 74 healthy controls (HCs) underwent resting-state functional and perfusion magnetic resonance imaging (MRI) scans as well as overnight polysomnography examination to assess brain function and REM%, with 48 patients completing follow-up visits. Correlation and mediation analyses were conducted to investigate the associations among baseline REM%, multimodal brain imaging measures, and the improvement of depressive symptoms at follow-up in MDD.

RESULTS

We found voxel-wise correlations between baseline REM% and multimodal brain imaging metrics in many brain regions involved in sensorimotor, visual processing, emotion, and cognition in patients with MDD. Moreover, the baseline REM% was correlated with the improvement of depressive symptoms from acute to remitted status in patients through regulating brain activity in the left inferior temporal gyrus and cerebral blood flow in the bilateral paracentral lobule.

CONCLUSION

Our findings help to identify the neural underpinnings of REM% in depression and highlight REM% as a potential prognostic biomarker to predict disease progression. These may inform future novel interventions of MDD from the perspective of regulating REM sleep.

Comparison of the usability of an automatic sleep staging program via portable 1-channel electroencephalograph and manual sleep staging with traditional polysomnography

Automatic algorithms are a proposed alternative to manual assessment of polysomnography data for analyzing sleep structure; however, none are acceptably accurate for clinical use. We investigated the feasibility of an automated sleep stage scoring system called Sleep Scope, which is intended for use with portable 1-channel electroencephalograph, and compared it with the traditional polysomnography scoring method. Twenty-six outpatients and fourteen healthy volunteers underwent Sleep Scope and polysomnography assessments simultaneously. Polysomnography records were manually scored by three sleep experts. Sleep Scope records were scored using a dedicated auto-staging algorithm. Sleep parameters, including total sleep time, sleep latency, wake after sleep onset, and sleep efficiency, were calculated. The epoch-by-epoch pairwise concordance based on the classification of sleep into five stages (i.e., wake, rapid eye movement, N1, N2, and N3) was also evaluated after validating homogeneity and bias between Sleep Scope and polysomnography. Compared with polysomnography, Sleep Scope seemed to overestimate sleep latency by approximately 3 min, but there was no consistent tendency in bias in other sleep parameters. The Κ values ranged from 0.66 to 0.75 for experts' inter-rater polysomnography scores and from 0.62 to 0.67 for Sleep Scope versus polysomnography scores, which indicated sufficient agreement in the determination of sleep stages based on the Landis and Koch criteria. We observed sufficient concordance between Sleep Scope and polysomnography despite lower concordance in sleep disorder patients. Thus, this auto-staging system might serve as a novel clinical tool for reducing the time and expenses required of medical staff and patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-022-00421-5.

Network Analysis of Depression, Anxiety, Posttraumatic Stress Symptoms, Insomnia, Pain, and Fatigue in Clinically Stable Older Patients With Psychiatric Disorders During the COVID-19 Outbreak

OBJECTIVES

The Coronavirus Disease 2019 (COVID-19) pandemic has profound negative effects on the mental health of clinically stable older patients with psychiatric disorders. This study examined the influential nodes of psychiatric problems and their associations in this population using network analysis.

METHODS

Clinically stable older patients with psychiatric disorders were consecutively recruited from four major psychiatric hospitals in China from May 22 to July 15, 2020. Depressive and anxiety syndromes (depression and anxiety hereafter), insomnia, posttraumatic stress symptoms (PTSS), pain, and fatigue were measured using the Patient Health Questionnaire, General Anxiety Disorder, Insomnia Severity Index, Posttraumatic Stress Disorder Checklist - Civilian Version, and Numeric Rating Scales for pain and fatigue, respectively.

RESULTS

A total of 1063 participants were included. The network analysis revealed that depression was the most influential node followed by anxiety as indicated by the centrality index of strength. In contrast, the edge connecting depression and anxiety was the strongest edge, followed by the edge connecting depression and insomnia, and the edge connecting depression and fatigue as indicated by edge-weights. The network structure was invariant by gender based on the network structure invariance test (M = .14, P = .20) and global strength invariance tests (S = .08, P = .30).

CONCLUSIONS

Attention should be paid to depression and its associations with anxiety, insomnia, and fatigue in the screening and treatment of mental health problems in clinically stable older psychiatric patients affected by the COVID-19 pandemic.

Sleep Disturbances and Their Association With Quality of Life in Older Psychiatric Patients During the COVID-19 Pandemic

AIMS

The negative effect of the COVID-19 pandemic on sleep quality of clinically stable psychiatric patients is unknown. This study examined the prevalence of sleep disturbances and their association with quality of life (QOL) in clinically stable older psychiatric patients during the COVID-19 pandemic.

METHODS

This multicenter, cross-sectional study involved older patients attending maintenance treatment at outpatient departments of four major psychiatric hospitals in China. Patients' socio-demographic and clinical characteristics were collected. Sleep disturbances, depressive symptoms, and QOL were assessed with the Insomnia Severity Index, the 9-item Patient Health Questionnaire, and 2 items of the World Health Organization Quality of Life-Brief version, respectively. Binary logistic regression analysis was conducted to examine the independent associations of socio-demographic and clinical variables with sleep disturbances, while the association between sleep disturbances and QOL was explored with analysis of covariance.

RESULTS

A total of 941 patients were recruited. The prevalence of sleep disturbances was 57.1% (95% CI: 53.9-60.2%). Analysis of covariance revealed that QOL was significantly lower in patients with sleep disturbances compared to those without. Multivariate logistic regression analysis showed that sleep disturbances were positively and independently associated with more severe depressive symptoms (OR = 1.32, 95% CI: 1.26-1.37). Compared to patients with major depressive disorder, those with other psychiatric diagnoses had a significantly higher prevalence of sleep disturbances (OR = 1.44, 95% CI: 1.00-2.08).

CONCLUSION

Sleep disturbances were common among clinically stable older psychiatric patients during the COVID-19 pandemic. Considering the negative association with QOL, this subpopulation needs regular assessment and timely treatment to reduce their sleep disturbances and improve their QOL.

Efficacy and safety of Qigong Baduanjin exercise in the treatment of depression with insomnia: A randomized controlled study protocol

BACKGROUND

Depression is a common mental illness often associated with insomnia. Baduanjin exercise has been found to improve depressive symptoms and has also been found to have good effects on insomnia. However, there are no rigorous clinical studies to evaluate the effects of Baduanjin exercise on depressed patients with insomnia, so this randomized controlled trial will evaluate the efficacy of Qigong Baduanjin exercise in treating depression with insomnia.

METHODS

This is a prospective randomized controlled trial to investigate the clinical efficacy of Baduanjin exercise in the treatment of depression with insomnia. The included patients will be randomly divided into a treatment group and control group. The treatment group will be treated with Baduanjin exercise and the control group will be treated with oral mirtazapine. After 8 weeks of continuous treatment, they will be followed up for 3 months. Observed indexes included Pittsburgh sleep quality index, Hamilton expression Rating Scale score, and adverse reactions. Finally, the data are statistically analyzed by SPSS 20.0 software.

DISCUSSION

This study will evaluate the efficacy and safety of Baduanjin exercise in the treatment of depression with insomnia, and the results of this study will provide a clinical basis for the treatment of depression with insomnia.Trial registration: OSF Registration number: DOI 10.17605/OSF.IO/KC48H.

Polysomnographic markers of suicidal ideation in untreated unipolar major depressed individuals

Given the major role played by sleep in the particular relationship between suicidality and major depression, the aim of this study was to empirically identify polysomnographic markers specific to suicidal ideation in major depressed individuals in order to allow better suicide prevention in this high-risk subpopulation. Demographic and polysomnographic data from 190 individuals (34 healthy controls and 156 untreated unipolar major depressed individuals) recruited from the sleep laboratory database were analysed. Suicidal ideation were considered present if the score in item G of the Beck Depression Inventory was ≥1 and/or if they were highlighted during the systematic psychiatric assessment conducted on admission to the sleep laboratory. Independently of depression severity, major depressed individuals with suicidal ideation present a decrease in deep NREM sleep (slow-wave sleep) and an increase in light NREM sleep (stage 1 + stage 2) compared to those without suicidal ideation. There are no significant differences for the other polysomnographic parameters. In our study, we highlighted the existence of potential polysomnographic markers of suicidal ideation in untreated unipolar major depressed individuals, which seems to open up new perspectives for the identification and management of individuals at high-risk of suicide in this particular subpopulation.

Preliminary Study on Changes of Sleep EEG Power and Plasma Melatonin in Male Patients With Major Depressive Disorder After 8 Weeks Treatment

Objective: To clarify the effects of escitalopram on sleep EEG power in patients with Major depressive disorder (MDD). Method: Polysomnography (PSG) was detected overnight, and blood samples were collected at 4 h intervals over 24 h from 13 male healthy controls and 13 male MDD patients before and after treatment with escitalopram for 8 weeks. The outcome measures included plasma melatonin levels, sleep architecture, and the sleep EEG power ratio. Results: Compared with healthy controls, MDD patients presented abnormalities in the diurnal rhythm of melatonin secretion, including peak phase delayed 3 h and a decrease in plasma melatonin levels at night and an increase at daytime, accompanied by sleep disturbances, a decrease in low-frequency bands and an increase in high-frequency bands, and the dominant right-side brain activity. Several of these abnormalities (abnormalities in the diurnal rhythm of melatonin secretion, partial sleep architecture parameters) persisted for at least the 8-week testing period. Conclusions: Eight weeks of treatment with escitalopram significantly improved subjective sleep perception and depressive symptoms of patients with MDD, and partially improved objective sleep parameters, while the improvement of circadian rhythm of melatonin was limited.

Brain mechanisms of insomnia: new perspectives on causes and consequences

While insomnia is the second most common mental disorder, progress in our understanding of underlying neurobiological mechanisms has been limited. The present review addresses the definition and prevalence of insomnia and explores its subjective and objective characteristics across the 24-hour day. Subsequently, the review extensively addresses how the vulnerability to develop insomnia is affected by genetic variants, early life stress, major life events, and brain structure and function. Further supported by the clear mental health risks conveyed by insomnia, the integrated findings suggest that the vulnerability to develop insomnia could rather be found in brain circuits regulating emotion and arousal than in circuits involved in circadian and homeostatic sleep regulation. Finally, a testable model is presented. The model proposes that in people with a vulnerability to develop insomnia, the locus coeruleus is more sensitive to-or receives more input from-the salience network and related circuits, even during rapid eye movement sleep, when it should normally be sound asleep. This vulnerability may ignite a downward spiral of insufficient overnight adaptation to distress, resulting in accumulating hyperarousal, which, in turn, impedes restful sleep and moreover increases the risk of other mental health adversity. Sensitized brain circuits are likely to be subjectively experienced as "sleeping with one eye open". The proposed model opens up the possibility for novel intervention studies and animal studies, thus accelerating the ignition of a neuroscience of insomnia, which is direly needed for better treatment.

Sleep disturbance and psychiatric disorders

Signs of mental ill health that cut across psychiatric diagnostic categories at high rates are typically viewed as non-specific occurrences, downgraded in importance and disregarded. However, problems not associated with particular diagnoses should be expected if there is shared causation across mental health conditions. If dynamic networks of interacting symptoms are the reality of mental health presentations, then particularly disruptive and highly connected problems should be especially common. The non-specific occurrence might be highly consequential. One non-specific occurrence that is often overlooked is patients' chronic difficulty in getting good sleep. In this Review, we consider whether disrupted sleep might be a contributory causal factor in the occurrence of major types of mental health disorders. It is argued that insomnia and other mental health conditions not only share common causes but also show a bidirectional relationship, with typically the strongest pathway being disrupted sleep as a causal factor in the occurrence of other psychiatric problems. Treating insomnia lessens other mental health problems. Intervening on sleep at an early stage might be a preventive strategy for the onset of clinical disorders. Our recommendations are that insomnia is assessed routinely in the occurrence of mental health disorders; that sleep disturbance is treated in services as a problem in its own right, yet also recognised as a pathway to reduce other mental health difficulties; and that access to evidence-based treatment for sleep difficulties is expanded in mental health services.

Alterations of neural network organization during REM sleep in women: implication for sex differences in vulnerability to mood disorders

BACKGROUND

Sleep plays an important role in vulnerability to mood disorders. However, despite the existence of sex differences in vulnerability to mood disorders, no study has yet investigated the sex effect on sleep network organization and its potential involvement in vulnerability to mood disorders. The aim of our study was to empirically investigate the sex effect on network organization during REM and slow-wave sleep using the effective connectivity measured by Granger causality.

METHODS

Polysomnographic data from 44 healthy individuals (28 men and 16 women) recruited prospectively were analysed. To obtain the 19 × 19 connectivity matrix of all possible pairwise combinations of electrodes by Granger causality method from our EEG data, we used the Toolbox MVGC multivariate Granger causality. The computation of the network measures was realized by importing these connectivity matrices into EEGNET Toolbox.

RESULTS

In men and women, all small-world coefficients obtained are compatible with a small-world network organization during REM and slow-wave sleep. However, compared to men, women present greater small-world coefficients during REM sleep as well as for all EEG bands during this sleep stage, which indicates the presence of a small-world network organization less marked during REM sleep as well as for all EEG bands during this sleep stage in women. In addition, in women, these small-world coefficients during REM sleep as well as for all EEG bands during this sleep stage are positively correlated with the presence of subclinical symptoms of depression.

CONCLUSIONS

Thus, the highlighting of these sex differences in network organization during REM sleep indicates the presence of differences in the global and local processing of information during sleep between women and men. In addition, this small-world network organization less marked during REM sleep appears to be a marker of vulnerability to mood disorders specific to women, which opens up new perspectives in understanding sex differences in the occurrence of mood disorders.

Impact of number of sleep ultradian cycles on polysomnographic parameters related to REM sleep in major depression: Implications for future sleep research in psychiatry

Given the contradictory data on REMS alterations in major depression, the aim of this study was to empirically demonstrate that based on the number of sleep ultradian cycles, it was possible to highlight different subtypes of major depression characterized by specific patterns of REMS alterations. Demographic and polysomnographic data from 211 individuals (30 healthy controls and 181 untreated major depressed individuals) recruited from the sleep laboratory database were analyzed. Major depressed individuals with sleep ultradian cycles <4 showed alterations consistent with REMS deficiency (non-shortened REM latency as well as decrease in REMS percentage, REMS duration and REMS/NREMS ratio) whereas major depressed individuals with sleep ultradian cycles >4 showed alterations consistent with REMS disinhibition (shortened REM latency as well as increase in REMS percentage, REMS duration and REMS/NREMS ratio). Regarding major depressed individuals with 4 sleep ultradian cycles, their REMS alterations were intermediate to those present in major depressed individuals with sleep ultradian cycles <4 and >4. Thus, in major depressed individuals, the highlighting of this heterogeneity of REMS alterations based on the number of sleep ultradian cycles seems to suggest the involvement of distinct pathophysiological mechanisms and could open new perspectives for future sleep research in psychiatry.

Alterations of neural network organisation during rapid eye movement sleep and slow-wave sleep in major depression: Implications for diagnosis, classification, and treatment

The aim of this study was to empirically investigate the network organisation during rapid eye movement sleep (REMS) and slow-wave sleep (SWS) using the effective connectivity measured using the Granger causality to identify new potential biomarkers for the diagnosis, classification, and potential favourable response to treatment in major depression. Polysomnographic data were analysed from 24 healthy individuals and 16 major depressed individuals recruited prospectively. To obtain the 19×19 connectivity matrix of all possible pairwise combinations of electrodes by the Granger causality method from our electroencephalographic data, we used the Toolbox MVGC multivariate Granger causality. The computation of network measures was realised by importing these connectivity matrices into the EEGNET Toolbox. Major depressed individuals (versus healthy individuals) and those with endogenous depression (versus those with neurotic depression) present alterations of small-world network organisation during REMS, whereas major depressed individuals with potential favourable response to electroconvulsive therapy (versus those with potential unfavourable response) have a less efficient small-world network organisation during SWS. Thus, alterations in network organisation during REMS could be biomarkers for the diagnosis and classification of major depressive episodes, whereas alterations of network organisation during SWS could be a biomarker to predict potential favourable response to treatment by electroconvulsive therapy.

Risk of resistant hypertension associated with restless legs syndrome and periodic limb movements during sleep: a study on 673 treated hypertensive individuals

OBJECTIVE

Given the limited data available in the literature, the aim of this study was to examine the risk of resistant hypertension (RHT) associated with restless legs syndrome (RLS) and periodic limb movements during sleep (PLMS) in a large sample of treated hypertensive individuals.

METHODS

Demographic and polysomnographic (PSG) data from 673 treated hypertensive individuals recruited from the research database of the sleep laboratory of Erasme Hospital were analysed. After exclusion of the main causes of pseudo-resistance and secondary hypertension, RHT status was defined by the presence of an uncontrolled hypertension despite treatment with at least three antihypertensive agents (including a diuretic) from different classes in correct combination and at the highest tolerated doses or by the presence of controlled hypertension requiring the use of at least four antihypertensive agents. Logistic regression analyses were conducted to examine the risk of RHT associated with RLS and PLMS in treated hypertensive individuals.

RESULTS

After adjustment for major confounding factors associated with RHT, multivariate logistic regression analysis revealed that frequent RLS (≥2 episodes/week) combined with PLMS index ≥26/h [odds ratio (OR) 2.20; 95% confidence interval (CI) 1.35-3.61, p = 0.021] was a significant risk factor of RHT in treated hypertensive individuals.

CONCLUSION

In treated hypertensive individuals, frequent RLS combined with PLMS index ≥26/h is associated with higher risk of RHT which suggests that this pathology may be a secondary cause of RHT (eg, obstructive sleep apnoea syndrome and insomnia with short sleep duration) justifying the establishment of effective treatments in this particular subpopulation.

Prevalence and risk factors of excessive daytime sleepiness in major depression: A study with 703 individuals referred for polysomnography

BACKGROUND

To date, few studies have investigated the prevalence and risk factors of excessive daytime sleepiness (EDS) in major depression. Thus, the aim of the present study was to examine the prevalence and risk factors of EDS in a large sample of individuals with major depression.

METHODS

Data from 703 individuals with major depression were retrospectively collected from the sleep laboratory research database of Erasme Hospital for analysis. A score of > 10 on the Epworth Sleepiness Scale was used as the cut-off for EDS. Logistic regression analyses were conducted to examine the clinical and demographic risk factors of EDS in major depression.

RESULTS

The prevalence of EDS in our sample was 50.8%. Multivariate logistic regression analysis revealed that the following were significant risk factors of EDS in major depression: non-use of short to intermediate half-life benzodiazepine receptor agonists, BMI ≥ 25 kg/m², age < 60 years, C-reactive protein > 7 mg/L, Beck Depression Inventory score ≥ 16, atypical depression, apnea-hypopnea index ≥ 15/h, and use of selective serotonin reuptake inhibitors or serotonin-norepinephrine reuptake inhibitors.

LIMITATIONS

To evaluate EDS, we used the Epworth Sleepiness Scale, which only allows for a subjective measure of daytime sleepiness.

CONCLUSION

EDS is a common symptom in individuals with major depression. In this subpopulation, interventions are possible for most risk factors of EDS, which justifies improved management of this symptom to avoid its negative consequences.

Risk of high blood pressure associated with objective insomnia and self-reported insomnia complaints in major depression: A study on 703 individuals

BACKGROUND

Since few studies have investigated the risk of high blood pressure associated with objective insomnia and self-reported insomnia complaints in major depression, the aim of this study was to examine this risk in a large sample of individuals with major depression.

METHODS

Data from 703 individuals with major depression recruited from the research database of the sleep laboratory of the Erasme Hospital were analysed. High blood pressure status was defined by the presence of one of the following: self-reports at interview of either a physician-diagnosis or taking antihypertensive medication; or an average systolic blood pressure ≥140 mmHg or an average diastolic blood pressure ≥90 mmHg during at least two medical examinations. Logistic regression analyses were conducted to examine the risk of high blood pressure associated with objective insomnia and self-reported insomnia complaints in major depression.

RESULTS

After adjustment for major confounding factors associated with high blood pressure, multivariate logistic regression analysis revealed that severe objective insomnia, low complaints of repeated nighttime awakenings or early morning awakening, and intermediate or low self-reported insomnia complaints were significant risk factors of high blood pressure in major depression.

CONCLUSION

In major depression, severe objective insomnia and lower self-reported insomnia complaints are associated with higher risk of high blood pressure, which justifies a better management of objective insomnia and a better assessment of insomnia complaints in this particular subpopulation to avoid the negative consequences related to the co-occurrence of high blood pressure and major depression. Abbreviations: AHI, Apnea-Hypopnea Index; BDI, Beck Depression Inventory; BMI, Body Mass Index; DSM IV-TR, Diagnostic and Statistical Manual of Mental Disorders fourth edition - Text Revision; ESS, Epworth Sleepiness scale; ISI, Insomnia Severity Index; HBP, High Blood Pressure; OSA, Obstructive Sleep Apnea Syndrome; REM, rapid eye movement sleep.

Objective sleep alterations and long-term use of short or intermediate half-life benzodiazepine receptor agonists are risk factors for high blood pressure in individuals with insomnia: a study in 1272 individuals referred for sleep examinations

INTRODUCTION

Given conflicting data in the literature, the aim of this study was to examine the risk of high blood pressure (HBP) associated with sleep alterations, measured during polysomnography, and long-term use of benzodiazepine receptor agonists in a large sample of individuals with insomnia.

METHODS

Demographic and polysomnographic data from 1272 individuals with insomnia recruited from the research database of the sleep laboratory of Erasme Hospital were analyzed. HBP status was defined by the presence of one of the following: self-report at interview of either a physician's diagnosis or taking antihypertensive medication; or an average systolic blood pressure ≥140 mm Hg or an average diastolic blood pressure ≥90 mm Hg at the medical examination. Logistic regression analyses were conducted to examine the risk of HBP associated with objective sleep alterations and long-term use of benzodiazepine receptor agonists in individuals with insomnia.

RESULTS

The prevalence of HBP in individuals with insomnia is 30.03%. After adjustment for major confounding factors associated with HBP, multivariate logistic regression analysis revealed that short sleep duration (<5 h), severely reduced sleep efficiency (<65%), high sleep fragmentation (sleep fragmentation index ≥18/h), and long-term use of short or intermediate half-life benzodiazepine receptor agonists were significant risk factors for HBP in individuals with insomnia.

CONCLUSION

In individuals with insomnia, objective sleep alterations and long-term use of short or intermediate half-life benzodiazepine receptor agonists are associated with higher risk of HBP. Therefore, better management of these reversible risk factors is required to avoid the negative consequences of the co-occurrence of insomnia and HBP.

The sleep network organization during slow-wave sleep is more stable with age and has small-world characteristics more marked than during REM sleep in healthy men

Sleep plays an important role in cognitive functioning. However, few studies have investigated the sleep network organization. The aim of our study was to empirically investigate the presence and the stability with age of a small-world network organization during REM and slow-wave sleep using the effective connectivity measured by the Granger causality. Polysomnographic data from 30 healthy men recruited prospectively were analysed. To obtain the 19 × 19 connectivity matrix of all possible pairwise combinations of electrodes by the Granger causality method from our EEG data, we used the Toolbox MVGC multivariate Granger causality. The computation of the network measures was realised by importing these connectivity matrices into the EEGNET Toolbox. Even if all small-world coefficients obtained are compatible with a small-world network organization during REM and slow-wave sleep, slow-wave sleep seems to have a small-world network organization more marked than REM sleep. Moreover, the sleep network organization is affected greater by age during REM sleep than during slow-wave sleep. In healthy individuals, the highlighting of a sleep network organization during slow-wave sleep more stable with age and with small-world characteristics more marked than during REM sleep may help to better understand the global and local processing of information during sleep.

Validity of Consumer Activity Wristbands and Wearable EEG for Measuring Overall Sleep Parameters and Sleep Structure in Free-Living Conditions

Consumer sleep tracking technologies offer an unobtrusive and cost-efficient way to monitor sleep in free-living conditions. Technological advances in hardware and software have significantly improved the functionality of the new gadgets that recently appeared in the market. However, whether the latest gadgets can provide valid measurements on overall sleep parameters and sleep structure such as deep and REM sleep has not been examined. In this study, we aimed to investigate the validity of the latest consumer sleep tracking devices including an activity wristband Fitbit Charge 2 and a wearable EEG-based eye mask Neuroon in comparison to a medical sleep monitor. First, we confirmed that Fitbit Charge 2 can automatically detect the onset and offset of sleep with reasonable accuracy. Second, analysis found that both consumer devices produced comparable results in measuring total sleep duration and sleep efficiency compared to the medical device. In addition, Fitbit accurately measured the number of awakenings, while Neuroon with good signal quality had satisfactory performance on total awake time and sleep onset latency. However, measuring sleep structure including light, deep, and REM sleep remains to be challenging for both consumer devices. Third, greater discrepancies were observed between Neuroon and the medical device in nights with more disrupted sleep and when the signal quality was poor, but no trend was observed in Fitbit Charge 2. This study suggests that current consumer sleep tracking technologies may be immature for diagnosing sleep disorders, but they are reasonably satisfactory for general purpose and non-clinical use.

Prevalence and risk factors of type 2 diabetes in insomnia sufferers: a study on 1311 individuals referred for sleep examinations

BACKGROUND

Several studies have investigated the particular relationship between insomnia and type 2 diabetes. However, few studies have investigated the prevalence and risk factors for type 2 diabetes in insomnia sufferers. The aim of this study was to examine the prevalence and risk factors of type 2 diabetes in a large sample of insomnia sufferers.

METHODS

Data from 1311 insomnia sufferers recruited from the research database of the Erasme Hospital sleep laboratory were analyzed. Only individuals with a diagnosis of type 2 diabetes according to the diagnostic criteria of the American Diabetes Association at admission were included in the diabetes group. Logistic regression analyses were conducted to examine clinical and demographic risk factors of type 2 diabetes in insomnia sufferers.

RESULTS

The prevalence of type 2 diabetes in insomnia sufferers is 21.13%. Multivariate logistic regression analysis revealed that significant risk factors of type 2 diabetes in insomnia sufferers were as follows: being male, Z-drugs use, high blood pressure, hypertriglyceridemia, alcohol consumption of ≥4 units/day, BMI ≥25 & <30 kg/m², BMI ≥30 kg/m², age ≥50 years, C-reactive protein ≥4.5 mg/L, a sleep duration of <6.5 h, apnea-hypopnea index ≥15/hour, periodic limb movements index ≥26/hour, and severe complaints of early morning awakening.

CONCLUSION

Type 2 diabetes is a common pathology in insomnia sufferers. In this subpopulation, most of the risk factors for type 2 diabetes are reversible, which justifies better prevention and management of this pathology in order to avoid its negative consequences.

Hyperarousal during sleep in untreated, major depressed subjects with prodromal insomnia: A polysomnographic study

In primary insomnia, specific dynamics of hyperarousal are evident during the night. Similarly, in major depression, many elements also favor of the presence of hyperarousal. Thus, it would be interesting to investigate if hyperarousal presents the same dynamic in major depression. Polysomnographic data from 30 healthy controls, 66 patients with major depression and prodromal insomnia, and 86 primary insomnia sufferers recruited from the sleep laboratory database were studied for whole night and thirds of the night. Insomnia sufferers and patients with depression exhibit a similar polysomnographic pattern both for whole night (increased sleep latency and WASO and reduced SWS and REM) and thirds of night (increased WASO at first and last thirds, reduced SWS in first third, and reduced in REM in first and last third). No alterations were detected during the second third of the night. Just as in primary insomnia, the hyperarousal phenomenon is found mainly in major depression with prodromal insomnia during the sleep-onset period and the first and last thirds of the night, but lesser during the second third of the night. These specific dynamics of hyperarousal may aid in the understanding of the particular relationship between insomnia and depression.